Select <exp>
From <t_name>
[where<cond>]
[group<col_name>]
[having by <group col_name>]
[order by <col_name>[asc|desc]];
Transaction Control Language(TCL) in SQL
Whenever DML operation is main in an oracle table, the transaction never be saved unless or until save command is issued or a discard is issued. TCL sublanguage is responsible data to do so TCL provide the following statement. --> Commit (save) --> Rollback (discard) --> Save point TCL mechanism: Whenever DML operation is made in oracle table just before a temporary memory is created in side in the sever technical is known as ROLLBACK SEGEMENT and the table on which the DML operation is going to be made is copied temporary to the rollback segment is known as snapshot. If commit command is issued from a sql prompt a rollback segment along with the snapshot gets deleted and the records transfer to main table will be permanent. If rollback command is issued from after DML operation a snapshot available inside the rollback segment again recopied to the original location with the old data and rollback segment gets deleted. NOTE: Data one committed cannot be rollback and rollba...
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